Since its creation on January 15, 2001, Wikipedia has grown rapidly into one of the largest reference websites, attracting 374 million unique visitors monthly as of September 2015[update].[1] There are about 68,000 active contributors working on more than 48,000,000 articles in 302 languages. As of today, there are 6,008,339 articles in English. Every day, hundreds of thousands of visitors from around the world collectively make tens of thousands of edits and create thousands of new articles to augment the knowledge held by the Wikipedia encyclopedia. (See the statistics page for more information.)
People of all ages, cultures and backgrounds can add or edit article prose, references, images and other media here. What is contributed is more important than the expertise or qualifications of the contributor. What will remain depends upon whether the content is free of copyright restrictions and contentious material about living people, and whether it fits within Wikipedia's policies, including being verifiable against a published reliable source, thereby excluding editors' opinions and beliefs and unreviewed research. Contributions cannot damage Wikipedia because the software allows easy reversal of mistakes and many experienced editors are watching to help ensure that edits are cumulative improvements. Begin by simply clicking the Editlink at the top of any editable page!

Wikipedia is a live collaboration differing from paper-based reference sources in important ways. Unlike printed encyclopedias, Wikipedia is continually created and updated, with articles on historic events appearing within minutes, rather than months or years. Because everybody can help improve it, Wikipedia has become more comprehensive than any other encyclopedia. In addition to quantity, its contributors work on improving quality as well. Wikipedia is a work-in-progress, with articles in various stages of completion. As articles develop, they tend to become more comprehensive and balanced. Quality also improves over time as misinformation and other errors are removed or repaired. However, because anyone can click "edit" at any time and add content, any article may contain undetected misinformation, errors, or vandalism. Awareness of this helps the reader to obtain valid information, avoid recently added misinformation (see Wikipedia:Researching with Wikipedia), and fix the article.

Wikipedia was founded as an offshoot of Nupedia, a now-abandoned project to produce a free encyclopedia, begun by the online media company Bomis. Nupedia had an elaborate system of peer review and required highly qualified contributors, but the writing of articles was slow. During 2000, Jimmy Wales (founder of Nupedia and co-founder of Bomis), and Larry Sanger, whom Wales had employed to work on the encyclopedia project, discussed ways of supplementing Nupedia with a more open, complementary project. Multiple sources suggested that a wiki might allow members of the public to contribute material, and Nupedia's first wiki went online on January 10, 2001.

There was considerable resistance on the part of Nupedia's editors and reviewers to the idea of associating Nupedia with a website in the wiki format, so the new project was given the name "Wikipedia" and launched on its own domain, wikipedia.com, on January 15 (now called "Wikipedia Day" by some users). The bandwidth and server (in San Diego) were donated by Wales. Other current and past Bomis employees who have worked on the project include Tim Shell, one of the cofounders of Bomis and its current CEO, and programmer Jason Richey.

The domain was eventually changed to the present wikipedia.org when the not-for-profit Wikimedia Foundation was launched, in 2003, as its new parent organization, with the ".org" top-level domain denoting its non-commercial nature. Today, there are Wikipedias in over 250 languages.

Wikipedia contributors

Anyone with Web access can edit Wikipedia, and this openness encourages inclusion of a tremendous amount of content. About 70,000 editors—from expert scholars to casual readers—regularly edit Wikipedia, and these experienced editors often help to create a consistent style throughout the encyclopedia, following our Manual of Style.

Several mechanisms are in place to help Wikipedia members carry out the important work of crafting a high-quality resource while maintaining civility. Editors are able to watch pages and technically skilled persons can write editing programs to keep track of or rectify bad edits. Where there are disagreements on how to display facts, editors often work together to compile an article that fairly represents current expert opinion on the subject. Aspiring authors may wish to read the information on Contributing to Wikipedia before contributing to the project.

Although the Wikimedia Foundation owns the site, it is largely uninvolved in writing and daily operations.

Most of Wikipedia's text and many of its images are dual-licensed under the Creative Commons Attribution-Sharealike 3.0 Unported License (CC-BY-SA) and the GNU Free Documentation License (GFDL) (unversioned, with no invariant sections, front-cover texts, or back-cover texts). Some text has been imported only under CC-BY-SA and CC-BY-SA-compatible license and cannot be reused under GFDL; such text is identified either on the page footer, in the page history or on the discussion page of the article that utilizes the text. Every image has a description page that indicates the license under which it is released or, if it is non-free, the rationale under which it is used.

Contributions remain the property of their creators, while the CC-BY-SA and GFDL licenses ensure the content is freely distributable and reproducible. (See content disclaimer for more information.)

Credits

Text on Wikipedia is a collaborative work, and the efforts of individual contributors to a page are recorded in that page's history, which is publicly viewable. Information on the authorship of images and other media, such as sound files, can be found by clicking on the image itself or the nearby information icon to display the file page, which includes the author and source, where appropriate, along with other information.

Exploring Wikipedia

Many visitors come to Wikipedia to acquire knowledge, while others come to share knowledge. At this very instant, dozens of articles are being improved, and new articles are also being created. Changes can be viewed at the Recent changes page and a random page at random articles. Over 5,600 articles have been designated by the Wikipedia community as featured articles, exemplifying the best articles in the encyclopedia. Another 30,000 articles are designated as good articles. Some information on Wikipedia is organized into lists; the best of these are designated as featured lists. Wikipedia also has portals, which organize content around topic areas. Articles can be found using the search box on the top-right side of the screen.

Wikipedia is available in languages other than English. Wikipedia has more than two hundred and eighty languages, including a Simple English version, and related projects include a dictionary, quotations, books, manuals, and scientific reference sources, and a news service (see sister projects). All these are maintained, updated, and managed by separate communities, and often include information and articles that can be hard to find through other common sources.

Basic navigation in Wikipedia

Wikipedia articles are all linked, or cross-referenced. When highlighted text like this is seen, it means there is a link to some relevant article or Wikipedia page with further in-depth information. Holding the mouse over the link will often show to where the link will lead. There are other links towards the ends of most articles, for other articles of interest, relevant external websites and pages, reference material, and organized categories of knowledge which can be searched and traversed in a loose hierarchy for more information. Some articles may also have links to dictionary definitions, audio-book readings, quotations, the same article in other languages, and further information available on our sister projects. Additional links can be easily made if a relevant link is missing—this is one simple way to contribute.

Using Wikipedia as a research tool

As wiki documents, articles are never considered complete and may be continually edited and improved. Over time, this generally results in an upward trend of quality and a growing consensus over a neutral representation of information.

Users should be aware that not all articles are of encyclopedic quality from the start: they may contain false or debatable information. Indeed, many articles start their lives as displaying a single viewpoint; and, after a long process of discussion, debate, and argumentation, they gradually take on a neutral point of view reached through consensus. Others may, for a while, become caught up in a heavily unbalanced viewpoint which can take some time—months or years perhaps—to achieve a better balanced coverage of their subject. In part, this is because editors often contribute content in which they have a particular interest and do not attempt to make each article they edit comprehensive. However, eventually, additional editors expand and contribute to articles and strive to achieve balance and comprehensive coverage. In addition, Wikipedia operates a number of internal resolution processes that can assist when editors disagree on content and approach. Usually, editors eventually reach a consensus on ways to improve the article.

The ideal Wikipedia article is well written, balanced, neutral, and encyclopedic, containing comprehensive, notable, verifiable knowledge. An increasing number of articles reach this standard over time, and many already have. Our best articles are called Featured Articles (and display a small star in the upper right corner of the article), and our second best tier of articles are designated Good Articles. However, this is a process and can take months or years to be achieved through the concerted effort of editors. Some articles contain statements which have not yet been fully cited. Others will later be augmented with new sections. Some information will be considered by later contributors to be insufficiently founded and, therefore, may be removed.

While the overall trend is toward improvement, it is important to use Wikipedia carefully if it is intended to be used as a research source, since individual articles will, by their nature, vary in quality and maturity. Guidelines and information pages are available to help users and researchers do this effectively, as is an article that summarizes third-party studies and assessments of the reliability of Wikipedia.

Wikipedia vs paper encyclopedias

Wikipedia has advantages over traditional paper encyclopedias. First, it is not limited in space: it can keep growing as fast as people add to it.

Second, there are no qualifications required to be able to author its articles. Therefore, it has a very large pool of contributors: the whole world. This, and the first advantage mentioned above, have enabled Wikipedia to become the most comprehensive encyclopedia on Earth.

Third, a paper encyclopedia remains static (stays the same) and falls out of date until the next edition. But Wikipedia is dynamic: you don't have to wait for the next edition to come out (there are no editions), as Wikipedia is published on-line as it is written on-line. Articles are made available as is, regardless of what stage of development they are in. You can update Wikipedia at any instant, and people do so continually around the clock, thereby helping each other to keep abreast of the most recent events everywhere and of the latest facts in every subject.

Fourth, Wikipedia has a very low "publishing" cost for adding or expanding entries, as it is on-line, with no need to buy paper or ink for distribution. This has allowed it to be made available for free, making it more accessible to everyone. This has enabled Wikipedia to be independently developed and published in many different languages at the same time, by people literate in each language. Of the 290+ different language Wikipedias, 137 of them have 10,000 or more articles.

Sixth, Wikipedia is extra-linear (more than linear). Instead of in-line explanations, Wikipedia incorporates hypertext in the form of wikilinks. Throughout its content is a robust network of links, providing another dimension of knowledge accessibility. The encyclopedia also has correlates to tables of contents and indexes, with each entry in them hyperlinked to an article on the topic specified.

Seventh, each Wikipedia article provides an introduction summarizing the more extensive detail of its contents.

Eighth, being open to anyone to edit, articles on Wikipedia are subject to additions that might be erroneous or written poorly, which in turn are subject to being corrected or rewritten. It is a community effort, with most people who are involved helping to improve the work, fixing problems they encounter along the way. See more about Wikipedia's strengths and weaknesses, below...

Strengths, weaknesses, and article quality

Wikipedia's greatest strengths, weaknesses, and differences all arise because it is open to anyone, it has a large contributor base, and its articles are written by consensus, according to editorial guidelines and policies.

Wikipedia is open to a large contributor base, drawing a large number of editors from diverse backgrounds. This allows Wikipedia to significantly reduce regional and cultural bias found in many publications, and makes it very difficult for any person or group to censor and impose bias. A large, diverse editor base also provides access and breadth on subject matter that is otherwise inaccessible or little documented. A large number of editors contributing at any moment can produce encyclopedic articles and resources covering newsworthy events within hours or days of their occurrence. Like any publication, Wikipedia may reflect the cultural, age, socio-economic, and other biases of its contributors. There is no systematic process to make sure that "obviously important" topics are written about, so Wikipedia may suffer unexpected oversights and omissions. While most articles may be altered by anyone, in practice editing will be performed by a certain demographic (younger rather than older, male rather than female, literate, rich enough to afford a computer, et cetera) and may, therefore, show some bias. Some topics may not be covered well, others in great depth.

Allowing anyone to edit Wikipedia makes it easily vandalized and susceptible to unverifed information, which requires removal. See Wikipedia:Administrator intervention against vandalism. While blatant vandalism is usually easily spotted and rapidly corrected, Wikipedia is more subject to subtle viewpoint promotion than a typical reference work. However, bias that would be unchallenged in a traditional reference work is likely to be eventually challenged or considered on Wikipedia. While Wikipedia articles generally attain a good standard after editing, it is important to note that fledgling articles and those monitored less well may be susceptible to vandalism and insertion of false information. Wikipedia's radical openness also means that any given article may be, at any given moment, in a bad state, such as in the middle of a large edit, or a controversial rewrite. Many contributors do not yet comply fully with key policies, or may add information without citable sources. Wikipedia's open approach tremendously increases the chances that any particular factual error or misleading statement will be relatively promptly corrected. Numerous editors at any given time are monitoring recent changes and edits to articles on their watchlists.

Wikipedia is written by open and transparent consensus—an approach that has its pros and cons. Censorship or imposing "official" points of view is extremely difficult to achieve and usually fails after a time. Eventually for most articles, all notable views become fairly described and a neutral point of view reached. In reality, the process of reaching consensus may be long and drawn-out, with articles fluid or changeable for a long time while they find their "neutral approach" that all sides can agree on. Reaching neutrality is occasionally made harder by extreme-viewpoint contributors. Wikipedia operates a full editorial dispute resolution process, one that allows time for discussion and resolution in depth, but one that also permits disagreements to last for months before poor-quality or biased edits are removed. A common conclusion is that Wikipedia is a valuable resource and provides a good reference point on its subjects.

That said, articles and subject areas sometimes suffer from significant omissions, and while misinformation and vandalism are usually corrected quickly, this does not always happen. (See for example this incident in which a person inserted a fake biography linking a prominent journalist to the Kennedy assassinations and Soviet Russia as a joke on a co-worker which went undetected for four months, saying afterwards he "didn’t know Wikipedia was used as a serious reference tool".)

Wikipedia is written largely by amateurs. Those with expert credentials are given no additional weight. Wikipedia is also not subject to any peer review for scientific, medical or engineering articles. One advantage to having amateurs write in Wikipedia is that they have more free time on their hands so that they can make rapid changes in response to current events. The wider the general public interest in a topic, the more likely it is to attract contributions from non-specialists.

The MediaWiki software that runs Wikipedia retains a history of all edits and changes, thus information added to Wikipedia never "vanishes" irreversibly. Discussion pages are an important resource on contentious topics. Therefore, serious researchers can often find a wide range of vigorously or thoughtfully advocated viewpoints not present in the consensus article. As with any source, information should be checked. A 2005 editorial by a BBCtechnology writer comments that these debates are probably symptomatic of cultural changes that are happening across all sources of information (including search engines and the media), and may lead to "a better sense of how to evaluate information sources".[3]

Disclaimers

Wikipedia disclaimers apply to all pages on Wikipedia. However, the consensus in Wikipedia is to put all disclaimers only as links and at the end of each article. Proposals to have a warning box at the beginning have been rejected. Some do not like the way it looks or that it calls attention to possible errors in Wikipedia.

Most articles start as stubs, but after many contributions, they can become featured articles. Once the contributor has decided a topic of interest, they may want to request that the article be written (or they could research the issue and write it themselves). Wikipedia has on-going projects, focused on specific topic areas or tasks, which help coordinate editing.

The ease of editing Wikipedia results in many people editing. That makes the updating of the encyclopedia very quick, almost as fast as news websites.

formatting elements and most world alphabets and common symbols, most of which have simple formats that are deliberately very easy and intuitive.

Normally editing is chosen by clicking the Edit tab at the top of a Wikipedia page (or on a section-edit link). This will take you to a new page with a text box containing the editable text of the page you were viewing. In this box, you can type in the text that you want to add, using wiki markup to format the text and add other elements like images and tables. You should then press the Show preview button to review your contributions for any errors. When you have finished editing, you should write a short edit summary in the small field below the edit-box describing your changes before you press the Publish changes button. This will help others to understand the intention of your edit. To avoid accidentally leaving edit summaries blank, you can select "Prompt me when entering a blank edit summary" on the Edit tab of your personal preferences.

Page editing is accessed through tabs that are found along the top edge of the page. These are:

Edit. This tab allows users to edit the article. Depending on the page’s susceptibility to vandalism, according to its visibility or the degree of controversy surrounding the topic, this tab may not be shown for all users. (For example, any user who is not an administrator will not be able to edit the Main Page.)

View history. This tab allows readers to view the editors of the article and the changes that have been made.

Star. ("Watch") If you are logged into your account, clicking on the star icon will cause any changes made to the article to be displayed on the watchlist. (Note: when this icon is clicked, it changes to a filled-in star.)

Wikipedia has robust version and reversion controls. This means that poor-quality edits or vandalism can quickly and easily be reversed or brought up to an appropriate standard by any other editor, so inexperienced editors cannot accidentally do permanent harm if they make a mistake in their editing. As there are many more editors intent on improving articles than not, error-ridden articles are usually corrected promptly.

Wikipedia:No original research, which prohibits the use of Wikipedia to publish personal views and original research of editors and defines Wikipedia's role as an encyclopedia of existing recognized knowledge;

Editorial administration, oversight, and management

Video guided tour #2: Why does Wikipedia work even though anyone can edit it?

The Wikipedia community is largely self-organising, so that anyone may build a reputation as a competent editor and become involved in any role s/he may choose, subject to peer approval. Individuals often will choose to become involved in specialised tasks, such as reviewing articles at others' request, watching current edits for vandalism, watching newly created articles for quality control purposes, or similar roles. Editors who believe they can serve the community better by taking on additional administrative responsibility may ask their peers for agreement to undertake such responsibilities. This structure enforces meritocracy and communal standards of editorship and conduct. At present a minimum approval of 75–80% from the community is required to take on these additional tools and responsibilities. This standard tends to ensure a high level of experience, trust, and familiarity across a broad front of aspects within Wikipedia.

Anyone can edit most of the articles here. Some articles are protected because of vandalism or edit-warring, and can be edited only by certain editors.

Anyone with an account that has been registered for four days or longer and has made at least ten edits becomes autoconfirmed, and gains the technical ability to do five things that non-autoconfirmed editors cannot:

Many editors with accounts obtain access to certain tools that make editing easier and faster. Few editors learn about most of those tools, but one common privilege granted to editors in good standing is "rollback", which is the ability to undo edits more easily.

Administrators ("admins" or "sysops") have been approved by the community, and have access to some significant administrative tools. They can delete articles, block accounts or IP addresses, and edit fully protected articles.

Bureaucrats are chosen in a process similar to that for selecting administrators. There are not very many bureaucrats. They have the technical ability to add or remove admin rights and approve or revoke "bot" privileges.

The Arbitration Committee is analogous to Wikipedia's supreme court. They deal with disputes that remain unresolved after other attempts at dispute resolution have failed. Members of this Committee are elected by the community and tend to be selected from among the pool of experienced admins.

Stewards hold the top echelon of community permissions. Stewards can do a few technical things, and one almost never hears much about them since they normally act only when a local admin or bureaucrat is not available, and hence almost never on the English Wikipedia. There are very few stewards.

Jimmy Wales, the founder of Wikipedia, has several special roles and privileges. In most instances, however, he does not expect to be treated differently than any other editor or administrator.

In addition, new users may initially find that their votes are given less weight by editors in some informal polls in order to prevent abuse of single-purpose accounts.

Editorial quality review

As well as systems to catch and control substandard and vandalistic edits, Wikipedia also has a full style and content manual and a variety of positive systems for continual article review and improvement. Examples of the processes include peer review, good article assessment, and the featured article process, a rigorous review of articles that are intended to meet the highest standards and showcase Wikipedia's capability to produce high-quality work.

Feedback and questions

Wikipedia is run as a communal effort. It is a community project whose result is an encyclopedia. Feedback about content should, in the first instance, be raised on the discussion pages of those articles. Be bold and edit the pages to add information or correct mistakes.

Frequently asked questions (FAQ)

Static help

The Help:Contents may be accessed by clicking help displayed under the ► Interaction tab at the top left of all pages.

Help:Menu—is a menu-style page that will direct you to the right place to find information.

Help:Directory—is a descriptive listing of all Wikipedia's informative, instructional and consultation pages.

Giving feedback

There is an established escalation-and-dispute process within Wikipedia, as well as pages designed for questions, feedback, suggestions, and comments. For a full listing of the services and assistance that can be requested on Wikipedia, see Wikipedia:Request directory.

Talk pages—the associated discussion page for discussion of an article or policy's contents (usually the first place to go)

Wikipedia:Vandalism—a facility for reporting vandalism (but fix vandalism as well as report it)

Because of the nature of Wikipedia, it is encouraged that people looking for information should try to find it themselves in the first instance. If, however, information is found to be missing from Wikipedia, be bold and add it so others can gain.

In addition, the Wikimedia Foundation Meta-Wiki is a site for coordinating the various Wikipedia projects and sister projects (and abstract discussions of policy and direction). Also available are places for submitting bug reports and feature requests.

Please note that while other sites may also use MediaWiki software and therefore look similar to Wikipedia, or may have a name that includes “Wiki-” or “-pedia”, or a similar domain name, the only projects which are part of the Wikimedia Foundation are those listed above and Wikipedia, even if other projects claim to be part of it.